Measures of acceleration in cosmology

Series: 
The London Relativity and Cosmology Seminar
Speaker: 
Phil Bull (Oxford)
Date: 
November 28th, 2012 at 16:30
Room: 
Maths 103
Abstract: 

A wide range of cosmological observations imply that the expansion of the Universe is accelerating -- if they are interpreted within a homogeneous and isotropic FLRW model. On considering inhomogeneous models, however, we find that "acceleration" becomes a rather ambiguous concept. In this talk, I describe how the question of whether spacetime is accelerating depends on what measure of acceleration is being used, and explain how this affects attempts to solve the dark energy problem.